1. Technical Field
The present invention relates to a method of liquid container, a method of manufacturing liquid container, a liquid container, remanufacturing method of liquid container, and remanufactured liquid container.
2. Related Art
As a liquid container, an ink cartridge removably mounted in an inkjet printer (hereinafter, referred to as a printer), which is a type of liquid ejection apparatus, for example, is known. The ink cartridge has a container body with a substantially flat box-like shape. An ink chamber is defined in the-container body to receive ink, which is liquid. An ink inlet hole is formed in a lower surface of the container body to allow initial filling of the ink into the ink chamber. An ink supply hole is also provided in the lower surface of the container body to receive an ink supply needle with the ink cartridge secured to the printer. To suppress leakage of the ink from the ink inlet hole and the ink supply hole, a cover film is bonded to the lower surface of the container body in such a manner as to seal the ink inlet hole and the ink supply hole.
After the ink cartridge is mounted in the printer, the printer consumes the ink through printing. This reduces the amount of the ink retained in the ink chamber until the ink cartridge becomes completely empty. The used ink cartridge is replaced by a new ink cartridge. The container body of the used ink cartridge is still usable for multiple cycles after the ink cartridge is removed from the printer. As disclosed in Japanese Registered Utility Model No. 3118670, a used ink cartridge may be remanufactured as a reusable ink cartridge by refilling the container body of the ink cartridge with ink. Such technique addresses to efficient use of resources and preservation of environments.
According to the technique of the above utility model, an opening is formed in the cover film at a position corresponding to the ink inlet hole using a piercing jig, before the used ink cartridge is refilled with ink. Then, a syringe, for example, is inserted into the ink inlet hole through the opening in the cover film to introduce the ink refill into the container body. Another film (a seal film) is then mounted on the cover film to close the opening and heated to be bonded to the cover film having the opening. In this manner, the opening is sealed and the ink is prevented from leaking from the opening.
To mount a new ink cartridge in the printer, an opening is formed in a portion of the cover film corresponding to the ink supply hole by an ink supply needle. Thus, after a used ink cartridge is refilled with ink, a seal film is welded to the cover film in such a manner that the seal film seals the opening in the cover film corresponding to the ink supply hole, in addition to the opening in the cover film corresponding to the ink inlet hole. When the thus remanufactured ink cartridge is installed in the printer, the ink supply needle penetrates the seal film and is received in the ink supply hole. This structure allows the ink to be supplied from the ink cartridge to the printer through the ink supply needle.
However, after the above-described remanufacturing procedure is repeatedly performed on the same ink cartridge, a plurality of seal films are welded to the cover film in a stacked state. The thickness of the stacked seal films as a whole is thus increased by the amount corresponding to the number of the repeated remanufacturing cycles. This changes the outer shape the ink cartridge, which may disadvantageously hamper, for example, installation of the ink cartridge at an optimal position with respect to the printer.
Further, the ink contaminates the cut pieces of the cover film (or the seal film) of the used ink cartridge that are formed around the opening formed by the ink supply needle. Prior to refilling the used ink cartridge with the ink, the portion of the cover film (or the seal film) around the opening is cleansed to remove the ink contaminating the cut pieces. However, after the ink cartridge is subjected to at least one cycle of remanufacturing, one or more seal films are provided on the cover film. If the seal films are stacked, ink may be caught between the cut pieces of an adjacent pair of the stacked films. Since it is not easy to cleanse and remove ink from between the stacked cut pieces, some of the ink may remain at the site without being removed. Thus, when the used ink cartridge is recovered and refilled with ink refill, the remaining used ink may mix with the new ink, or the ink refill, thus changing the composition of the ink.